The invention relates to a lead seal for sealing an opening, the lead seal being introduced into the opening in an insertion direction, having a base body, having a lateral projection which protrudes towards the insertion direction and is connected to the base body by means of a desired breaking point, which projection limits the insertion movement of the lead seal into the opening by means of bearing against a bearing face and shaves off after this bearing when there is a continued insertion movement, the base body being provided, on the side pointing in the insertion direction, with a hook which can be latched with a corresponding latching projection which is arranged opposite the plane enclosed by the limiting contour of the opening to be sealed. In addition, an arrangement having a housing is the subject matter of the invention, comprising a first housing part and a second housing part, which housing parts can be joined together, the first housing part having an opening, which opening is sealed, in the joined state, by means of a lead seal which is introduced into the opening in an insertion direction, the lead seal having a base body which is provided with a shaped section which limits, in an interlocking manner, the ability of the lead seal to move in the insertion direction.